(1) Field of the Invention
The present invention relates to an image forming method and an image forming apparatus therefor whereby an original is electronically read and the original image data can be processed by various editing functions to add effective representation to the original image. More detailedly, the present invention relates to an image forming apparatus having the function of reading a large-sized original, greater than the maximum original size the original table can handle, part by part, by multiple scans using a scanner or the like and reproducing the original image by joining the thus obtained sets of image data of the partial images of the original to be a single set of image data.
(2) Description of the Prior Art
Conventionally, as disclosed, for example, in Japanese Patent Application Laid-Open Hei 7 No. 131,631, image forming apparatuses such as digital copiers have been known which have an image editing function of reading an original greater in size than the maximum original to be set on the original table, part by part, by multiple scans and reproducing the original image by joining the thus captured partial images of the original as a single image.
In reading the original image in parts by multiple times, this image forming apparatus reads adjoining partial images in an overlapping manner, storing multiple partial images of data having common areas into the storage and then implementing pattern matching with respect to the overlapping areas, producing the original image data, composed of multiple partial images joined, in the memory, converting the image data into one having a size corresponding to that of the image to be reproduced, etc., and outputting the image on the designated recording medium through an image outputting means.
The conventional image forming apparatus having an image joining function, however, suffers from the following problems.
That is, the conventional configuration joins multiple sets of image data to once produce a bulky amount of original image data in the memory and stores it therein, so the storage device needs to have a large storage capacity, increasing the apparatus"" cost.
For example, when the apparatus has an A3-sized original table and an A2-sized original needs to be copied, the original is divided in parts of A3 size and stored into the storage device. Therefore the storage device needs a storage capacity of A2 size. Further, pattern matching between the partial images, using the common areas thereof, needs a large amount of storage capacity and requires a extensively long processing time.
Moreover, for producing an image of A2 size after the matching process, a very long time is needed for connection processing.
Besides, when the placement of the original is skewed (angled), the area to be searched for matching increases. Resultantly, the time and storage capacity required for matching would increase. Further, the process needs so-called affine transformations such as image rotation, translation, enlargement/reduction, etc., requiring a very long time, making it impossible to meet a practical level of processing time.
Furthermore, when connection processes such as pattern matching etc., are implemented, it is necessary to capture common image areas from the partial images of an original as they are picked up by multiple scans, part by part. In such a case where a large-sized original needing pattern matching is read, when the original is set on the original table it is not easy to decide the reference point, based on which the original will be put with respect to the original table. So it was difficult to select and define the overlapped image used for pattern matching between the first partial image of the original to be read first and the second partial image of the original to be read next.
It is therefore an object of the present invention to provide an image forming method and an image forming apparatus, which can solve the above problems and whereby a large-sized original greater than the maximum size to be placed on the original table can be copied in a correct and simple manner with a low cost configuration.
In order to achieve the above object, the present invention is configured as follows:
In accordance with the first aspect of the present invention, an image forming method for duplicating an original image having a size greater than the maximum size to be placed on the original table, comprises the steps of:
dividing the original image into a multiple number of partial images having a size equal to or smaller than the maximum placement size;
scanning adjoining partial images in a partially overlapped manner to supply multiple sets of partial images of data;
converting the, supplied, multiple partial images of data into reduced, partial images of data by reduction at a desired ratio;
storing the converted, reduced partial images of data into multiple storage areas;
effecting pattern matching by comparing adjoining reduced partial images of data as to the overlapping image data;
setting a joining position address that corresponds to the joining position in each storage area of reduced image data, based on the result of the pattern matching;
outputting the multiple reduced images of data stored in the different storage areas in a sequentially joinable manner; and
reproducing a reduced image of the original on the predetermined recording medium in accordance with the reduced partial images of data sequentially output in a joining manner.
In accordance with the second aspect of the present invention, an image forming apparatus for duplicating an original image having a size greater than the maximum size to be placed on the original, comprises:
an original image scanning means which successively scans a multiple number of partial images of an original, each divided to a size equal to or smaller than the maximum size of the original table, in a manner that produces at least an overlapping area between adjoining partial images, and supplies the multiple partial images of data;
an image reducing means converting the multiple partial images of data supplied from the original image scanning means into reduced partial images of data, reduced at a desired ratio;
a reduced partial image data storing means for storing each reduced partial image of data produced by the image reducing means;
a pattern matching means for implementing pattern matching based on the overlap image data between the adjoining, reduced partial images of data;
an address setting means for setting a joining position address that corresponds to the joining position in each storage area of reduced image data, based on the result obtained from the pattern matching means;
a data output control means which, based on the joining position addresses, outputs the multiple reduced partial images of data stored in respective storage areas, in a sequentially, joinable manner; and
an image forming means for forming a reduced image of the original on a predetermined recording medium in accordance with the image data output from the data output control means.
In accordance with the third aspect of the present invention, an image forming apparatus for duplicating an original image having a size greater than the maximum size to be placed on the original table, comprises:
a reference plate disposed so as to extend in one direction over the original table and having a side edge which forms the datum for the placement of an original;
an original image scanning means for capturing the image of an original placed abutting against the side edge of the reference plate, part by part, by multiple scans, to produce and supplies multiple partial images of data containing an overlapping area between adjoining partial images;
a connection relationship determining means for determining the connection relationship between adjoining multiple partial images of data of the original, based on the image data of the original image, within the joining range which extends perpendicularly to the reference plate with a predetermined width;
a data output control means for joining the multiple partial images of data of the original to produce integrated image data of the original, based on the connection relationship determined by the connection relationship determining means; and
an image forming means for forming an image of the original on a predetermined image medium, based on the image data output from the output control means, and is characterized in that the reference plate has a range mark displaying the joining area and a reference indicator within the range mark.
In accordance with the fourth aspect of the present invention,
The image forming apparatus having the above third feature is characterized in that the reference indicator is located at the center of the range mark with respect to the extended direction of the reference plate.
In accordance with the fifth aspect of the present invention, the image forming apparatus having the above second feature, further comprises an original pressing member for fixing the original onto the original table.
In accordance with the sixth aspect of the present invention, the image forming apparatus having the above third feature, further comprises an original pressing member for fixing the original onto the original table.
In accordance with the seventh aspect of the present invention, the image forming apparatus having the above fourth feature, further comprises an original pressing member for fixing the original onto the original table.
In accordance with the above configuration of the present invention, when, for example, an original is read as two partial images, by two scans (the 1st and 2nd scans) to obtain the image data, the apparatus, based on the result of pattern matching, generates joining position addresses, directly outputs the partial images of data, instead of producing a synthesized image in the memory, switching from one to the other in accordance with the joining position addresses, to thereby produce a reduced, duplication image by joining multiple reduced partial images of data.
Further, in accordance with the present invention, a pair of marks added at the opposing positions on both sides of the original or a fold of the original, can be set, on the original table, in alignment with the reference indicator provided within the range mark displaying the pattern matching area, so that it is possible to more reliably capture the image of the area required for joining the partial images of the original.
Moreover, when, in a configuration where the reference indicator is provided at the center of the range mark, the original is set so that a pair of marks added at the opposing positions on both sides of the original, or a fold of the original is in alignment with the reference indicator, it is possible to reliably capture the partial images whilst suppressing the area required for image joining to the minimum.
Finally, in all configurations of the present invention described above, when pressing members for fixing the original onto the original table are provided so as to prevent unintentional rotation or other movement of the original, it is possible to further efficiently effect the image forming operation in the image joining mode, without needing any correcting treatments required due to the rotation of the image.